Hi to all. This time I try to make the SIO2SD in micro version, and I like to think that I succeeded! As is, the size is identical to that of SDrive micro.As regards the construction I have followed closely the design of original "version 2" schematic from SIO2SD wiki, but redesigned to a smaller pcb with smd parts.The sd socket is push-push type, and the lcd screen is green backlighted with 2x16 characters mini display. Sorry for the green color, but is the only one I found available in this dimension, and at this price also!Now the heart of the device the ATmega32A microcontroller, is the latest and optimized one with minimal consumption against the previous ATmega32-16. You can read for the migrating in the above link.http://www.atmel.com...ges/doc8162.pdf

The 5 button have the same place and meaning as the original SIO2SD in its wiki page.Internally a ISP connector exist for any update with a programmer. Alternative can be the same with the procedure of "Shift" + "K3" buttons.The pull up resistor for the maximum 127Kb/s high speed, exist also in circuit.The device is programmed with the latest firmware 3.1RC2, and work perfect with 3.5 fast loader.

Now about the plastic enclosure.Because of the lcd display, isn't possible for me with conventional tools to make the hole. The result at least in my eyes is not acceptable, and of course, besides taking a long time to make. For that I addressed this in a local company with a cnc router, and which to arrive at a reasonable price, need to make minimum 50 enclosures. If you do like what you see and want to order one, as we all understand to be able to order materials should have at least 40 preorders...The final price for this number of devices can be at 50 euros for each one.

Last the plastic enclosure of device shown in the photos, is hand made and used as a Demo. For that reason have some imperfection in the cut of the hole for the lcd. The final one if ever exist, will be flawless cut for all holes from professional cnc router.Thank you all for your time.

Nice. What would be "nicer" is the option for a header that handles the buttons so you can relocate them wherever you want.
My SIO2SD is still bare, the overall design doesn't lend well to putting into a case without first doing mods to it.

Ideally I'd put one inside a machine or two if the price point was right.

Owners of santosp's previous SDrive micro know the quality of his products and his flawless shipping.The price is very low compared with other SIO2SDs on the market.I hope it will have the success it deserves.I will add it in the Topic for newbies. Added in Topic for newbies.

Hi to all. Last the plastic enclosure of device shown in the photos, is hand made and used as a Demo. For that reason have some imperfection in the cut of the hole for the lcd. The final one if ever exist, will be flawless cut for all holes from professional cnc router.Thank you all for your time.

As for the Mega-HZ device, if he can show this complete with enclosure and SIO cable to 50 euros, then YES!
Ladies and gentlemen we have an opponent! I wish my attempt to make the other atari devices, most intergrated and cheaper simultaneously.

As for the Mega-HZ device, if he can show this complete with enclosure and SIO cable to 50 euros, then YES!Ladies and gentlemen we have an opponent! I wish my attempt to make the other atari devices, most intergrated and cheaper simultaneously.

I would agree that for a complete cased unit your version is a good value, for putting inside an Atari computer or other desired enclosure think the Megahz version would be better. Its' mounting holes line up well enough that the circuit board and display can become a single unit if desired, and the switches/LEDs being in a single row simplifies case modification a bit.

From your silkscreen markings it appears that you didn't follow his example in replacing the 74HC245 with a 74LVC125, this was to provide a lower voltage IO signal to the SD card.

if you leave it like it is now, with hc245 chip, it will kinda work
best would be to put cpu and sd card on the same logic levels (3.3V) and buffer sio signals with lvc/lvc125 chip
also, you need a reservouar cap as close to the sd card connector as possible (47uF will suffice)

Please guys dont compare my device with Mega-HZ one. Besides, this is not the purpose of the topic.

I would agree that for a complete cased unit your version is a good value, for putting inside an Atari computer or other desired enclosure think the Megahz version would be better. Its' mounting holes line up well enough that the circuit board and display can become a single unit if desired, and the switches/LEDs being in a single row simplifies case modification a bit.

I would agree with you but I do not sell a generic structure to put it where everyone wants! My construction is complete with enclosure and cable, ready to run! So what would be fair to do the comparison and to export any results, with another device in the same class.

From your silkscreen markings it appears that you didn't follow his example in replacing the 74HC245 with a 74LVC125, this was to provide a lower voltage IO signal to the SD card.

No I didn't follow nothing from his work. After some discussion with the inventer I decide to "tack with its own water". But.....After all what is the problem? The device is here and work perfect with last firmware revision,

if you leave it like it is now, with hc245 chip, it will kinda work

Hi Sebastian! Can you suggest some programs that may experience glitches to try them in this construction?Also what happen with the cart project? I have long time to hear from you.

Panos, it's not about programs, it's about SD cards - it works with some of them, but not all of them, and it may vary from device to device - all this because of marginal IO logic levels present in this design
with SDrive you were safe because whole thing runs at 3.3V, here you have mixed 5V and 3.3V lines, and to make matters even worse, both are CMOS
as for the cartridge - you wanted me to evaluate feasibility and fitabliity of some vhdl code i need to write, thus, it will take some time, since my resources are elsewhere

if you leave it like it is now, with hc245 chip, it will kinda workbest would be to put cpu and sd card on the same logic levels (3.3V) and buffer sio signals with lvc/lvc125 chipalso, you need a reservouar cap as close to the sd card connector as possible (47uF will suffice)

don't copy errors that original authors made

Panos, it's not about programs, it's about SD cards - it works with some of them, but not all of them, and it may vary from device to device - all this because of marginal IO logic levels present in this designwith SDrive you were safe because whole thing runs at 3.3V, here you have mixed 5V and 3.3V lines, and to make matters even worse, both are CMOS

From your silkscreen markings it appears that you didn't follow his example in replacing the 74HC245 with a 74LVC125, this was to provide a lower voltage IO signal to the SD card.

No I didn't follow nothing from his work. After some discussion with the inventer I decide to "tack with its own water". But.....After all what is the problem? The device is here and work perfect with last firmware revision,

The main problem with the HC245 is that a high level on the (Atmel-side) inputs will drive VCC of the SDcard from 3.3V to something like 4.5V. So far most cards seem to have survived this, but it's definitely a very bad idea...

Hi sloopy. As you can see very clearly, untill now none post the alternative circuit! Maybe is a TOP SECRET? Untill it down to, as you understand I must go with the existing from the inventer.

Please guys to restore the matter to the original flow, this thread isn't about Mega-HZ device. Has to do entirely with my own version. Once more, is the latest version from original manufacturer and WORKS PERFECT with my Atari in latest 3.5 firmware.Please let the post to run about the "Interest".